<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>select</title>
</head>
<body>
<p>select</p>
<select>
    <option th:each="city:${citys}" th:value="${city.key}" th:text="${city.value}" th:selected="${city.value} eq ${choice}"></option>
</select>
</body>
</html>